Dark matter halo concentrations: a short review

This review analyzes the state and advancement of the dark matter halo concentrations over the last two decades. It begins with presenting the article that brought the field to the limelight and then follows through with other research works that studied the concentrations of dark matter haloes over the ages. Besides the discussion of the halo mass-concentration relation and its evolution, we examine the effects of cosmology, subhaloes and environment on the relation. In addition to theoretical halo concentrations, observational dark matter halo concentrations are also considered. This review synthesizes the progress in this field into a clear piece of article.